
B–63172EN/01
5. REFERENCE POSITION
NC FUNCTION
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The machine is moved to a position to be specified as its reference
position, for example, in the jog feed mode. Setting the reference position
external setting signal to 1 specifies the current position of the relevant
axis as the reference position.
(1)Move the machine to a position to be specified as the reference
position, for example, by jogging.
(2)Select the jog feed (JOG) mode, and set the ZRN (bit 7 of G043) signal
to 1.
(3)Set the reference position external setting signal (ZPEXTn)
corresponding to the axis for which the reference position is to be set
up to 1. The reference position is set up for the specified axis.
The linear scale with absolute addressing reference marks has reference
marks (one–rotation signals) at intervals that change at a constant rate.
By determining the reference mark interval, the corresponding absolute
position can be deduced. The CNC makes a small movement along an
axis to measure the one–rotation signal interval, then calculates the
absolute position. The reference position can be established without
performing positioning to the reference position.
50.0
50.2
8.0
42.0 8.2 41.8 8.4 41.6 8.6 41.4
Reference marks
Reference mark 1
Reference mark 2
Fig. 5.9 Sample linear scale with absolute addressing reference marks
5.8
REFERENCE
POSITION
EXTERNAL SETTING
Basic procedure for
reference position
external setting
5.9
LINEAR SCALE WITH
ABSOLUTE
ADDRESSING
REFERENCE MARKS